Improvement in electric annunciators



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a. B. scan.

- Electric-Annunciato rsr No. 155,392, Patented Sept. 29,18 74.

"nunium v I Qfrmr UNITED STATES PATENT Orrron GEORGE E. SCOTT, OFBROOKLYN, NEW YORK, ASSIGNOR TO HIMSELF AND WILLIAM H. MARKLAND, OF SAMEPLACE.

IMPROVEMENT IN ELECTRIC ANNUNCIATORS.

Specification forming part of Letters Patent No. 155,392, datedSeptember 29, 1874; application filed December 18, 1873.

To all whom it may concern:

Be it known that I, GEORGE B. Scorr, of Brooklyn, in the county of Kingsand State of New York, have invented an Improvement in ElectricAnnunciators, of which the following is a specification:

The object of this invention is to exhibit a number or lettercorresponding to the room sending the signal, and to ring a bell; also,

' to continue the signal until the call is answered.

I make use of a galvanometer coil and swinging needle carrying thenumber or letter, or a shield for a stationary number or letter, andconnect the same in a branch of the main circuit, which main circuitalso passes through a relay-magnet, so that when either branch of themain circuit to the respective rooms is closed the relay-magnet operatesto close a local circuit and ring a bell, preferably continuously, untilthe branch circuit is opened and the relay demagnetized, and the numberor letter signal is obscured.

By this arrangement any number of rooms can be connected by branches toa main circuit. The galvanometer of the branch will indicate the signalof that branch, and the bell will be sounded until the relay-magnet isdemagnetized; hence, at the annunciator a signal will be continueduntihthe call is answered, and the branch circuit opened by thewithdrawal of the circuit-closer.

1n the drawing, Figure 1 is a general plan of the annunciator. Fig. 2 isa side View of the galvanometer-signal; and Fig. 3 is a diagram of theconnections.

The galvanometer-signa-l is made of three astatic needles, a, a, and c,hun g upon an axis, 11, and polarized in opposite directions. The needle0 is between the coil d of covered wire, and the needles 0. a areoutside the same. The coil 01 is wound so that the ends are broad, andit is contracted toward the middle, as seen in Fig. 2, in order that thebroad ends of such coil may act more directly upon the needles, and thecoil will not be in the way of the axis 11. i

By this construction of galvanometer the power of the needle is greatlyincreased without varying the battery-power, and hence it is betteradapted to the rough usage to which. it is exposed in an annunciator.

The signal-card e is attached to the needles to a, and contains theletter or number to be exhibited, or else the said card 0 uncovers orexposes such number or letter, if stationary; or the needle itself maygive the signal.

' When the number or letter is upon the card 0, the case of theannunciator is to be provided with inspection-openings in the plate h.One of these galvanometers is in each branch circuit z, and such circuitleads to the room with a corresponding, number; thence to the maincircuit is and battery, and in this circuit is the relay-magnet m;hence, when any branch circuit is closed at any room, the correspondinggalvanometer-sighal is deflected, and the relay-magnet closes the localcircuit 'v' to the magnet of the bell 0, the connections of which aremade as shown, so that the stroke of the bell breaks the circuit to itsown magnet, and the return of the hammer closes it again; hence the bellcontinues to ring as long as the local circuit is closed by therelaymagnet.

As a convenient means for closing the branch circuit, I prefer, and use,the divided plate .5, to which the branch-circuit wires are connected,and the movable spring metallic peg r is placed into the hole betweenthe plate 8, to close the branch circuit.

A switch might be used for the same purpose; but in either case thecircuit will remain closed until the switch is moved or the pegwithdrawn, thus insuring the attention of the waiter and the withdrawalby him or at his request of the circuit-closer.

It is preferable to employ astatic needles in the galvanometer, as theyoperate with a less battery-current; but a single galvanometcrsignalneedle may be used, if desired.

I am aware that electro-magnets and armatures have been employed inannunciators and alarms, but these are much more expensive thangalvanometer-coils, and are more liable to derangement from residualmagnetism and from inaccuracy of adjustment.

I claim as my invention 1. The combination, with an annunciatorspecified, in.combination with the signal of apparatus, of a plug orswitch circuit-closer, an annunciator, as set forth. a soundingapparatus, a relay, and main and Signed by me this 13th day of December,local circuits, substantially as set forth, where- A. D. 1873.

by the sounding apparatus is arranged to op- I v erate until the circuitis broken at the room, I SCOTT as specified. VVitness'es:

2. A galvanometer-coil and three needles, GEO. T. PINCKNEY,

constructed and arranged substantially as CHAS. H. SMITH.

